A conventional optical method and system for identifying a personal fingerprint is disclosed in Publication Gazettes of Unexamined Japanese Patent Application Hei 1-119881 and 1-119882. These publications disclose a method where a finger is put on a picture image inputting surface of a fingerprint identification device. A light beam is radiated from a light source for illuminating the finger, and the reflected light beam from the finger is inputted to the fingerprint identification device. The light beam is deflected by a mirror, focused by a pair of cylindrical lenses and inputted to a line charge coupled device (CCD) sensor through a pair of spatial filters, located in the fingerprint identification device.
The conventional method or system for identifying a fingerprint, however, requires independent optical elements such as a mirror, cylindrical lenses, spatial filters and the like for radiating the light beam and focusing the reflected light beam. Thus, it is difficult to make the conventional fingerprint identification system small.